Civil Engineering Interview Questions and Answers

Q1. Name various authorities or workers on a construction site?

• Senior Engineer/Project manager
• Site Engineer
• Contracter
• Mistri
• Mason/labor

Q2. What are the functions of column in a building?
Column is a verticle member in building whose primary function is to support structural load and transfer it through beams. Upper columns transfers the load to the lower columns and finally to the ground through footings.

Q3. What is the Unit Weight of concrete?
The unit weight of concrete depends on the type of aggregates and amount of voids. As per IS : 456-200 Unit weight of PCC is 24KN/m3 and RCC is 25KN/m3

Q4. What is ductility?
Ductility is the Ability to deform under tensile stress.

Q5. What is the cement sand & aggregate ratios for various grades of concrete mix?

• M10 – 1:3:6
• M15 – 1:2:4
• M20 – 1:1.5:3
• M25 – 1:1:2
• M30 – 1:1:1

Q6. What do you mean by honeycomb in concrete?
Honeycomb, also known as airpocket, is nothing but the air voids in concrete. It is usually formed during concrete casting.

 Q7. What is flat slab?
The slab which is supported on columns (Flab slab don’t have beams)

Q8. What do you mean by One storeyed, Two storeyed building?
The building which has two floors is called two storeyed building.

Q9. What do you mean by the moment of inertia?
A quantity expressing a body’s tendency to resist angular acceleration, which is the sum of the products of the mass of each particle in the body with the square of its distance from the axis of rotation.

Q10. What are the types of a slump?
True Slump: The concrete mass after the test when slumps evenly all around without disintegration is called the true slump.
Shear Slump: When one-half of the concrete mass slide down the other is called the shear slump. This type of slump is obtained in a lean concrete mix.
Collapse Slump: When the sample is collapsed due to adding excessive water, it is known as collapse slump.
Zero Slump:  For very stiff or dry mixes it does not show any changes of the slump after removing the slump cone.

Q11. What is the initial and final setting time of ideal cement mix?
Initial setting time for ideal cement mix is around 30 minutes for almost all kind of cements. For masonry cement it can be 90minutes. Final setting time of ideal cement mix should be 10 hours at max. For masonry cement it shouldn’t exceed 24hours.

Q12. What are common methods of curing the concrete?

• Spraying
• Wet covering of Surface
• Ponding
• Application of curing chemicals
• Steam curing

Q13. What do you know about “TMT”?
TMT stands for “Thermo Mechanically Treated”. Generally we use TMT bars and sheet for construction purposes for the reason that they have high strength and high corrosion resistance compared to normal steels.

Q14. What is difference between working stress method and limit state method?
Working stress method is an elastic design method in which structure is designed to bear the load upto elastic limit. Whereas, limit state method is a plastic design method in which structure is designed to bear the load beyond plastic limit.

Q15. What field tests are required for quality check of cement?
Quality of cement can be checked with color, physical properties, etc. Cement should have grey color with light greenish shade. It should feel smooth when rubbed between fingers. If hand is inserted in a heap of cement or its bags, it should feel cool. When pinch of cement is thrown in Water then cement should float for some time before it sink. Also, it should be lump free.

Q16. What are the types of foundation used in construction?
There are basically two types of foundation: Shallow & Deep foundation. Again shallow foundation can be classified as spread footing, combined footing, strap or cantilever footing and finally mat or raft footing. Deep foundations can be classified as pile footing, pier footing, caissons footing and well foundation.

Q17. What are the types of cement?
There are various types of cement which are: Ordinary Portland Cement (OPC), White Portland Cement (WPC), Portland Pozzolana Cement (PPC), Low Heat Portland Cement, Coloured Portland Cement, Hydrophobic cement, Rapid Hardening Cement, Portland Slag Cement, Sulphate resisting Portland Cement, etc.

Q18. What is guniting?
It is a process in which mixture of cement & sand in proportion of 1:3 is shooted on concrete surface with the help of cement gun under pressure of 2 to 3 kg/cm². It is a highly effective process for repairing concrete walls or damaged surfaces.

 Q19. What is the function of sand in mortar?
The main role of sand (aggregate) in mortar or plaster is to provide core strength, but it has other benefits too. If water is mixed with binder without adding sand to the mixture, both compressive and tensile strength of the mixture would be drastically lower than in mixture with added sand. It also helps to prevent mortar shrinkage, increases density and helps in setting.

Q20. What are various tests for checking brick quality?
We can use water absorption test, hardness test, shape & size, crushing strength test, soundness test, etc. to check the brick quality. In water absorption test, we dip the brick for 16 hours in water. If weight of brick after dipping in water doesn’t exceed by 20%, it can be considered as first class brick, if below 22.5% it can be considered as second class brick, if below 25% it can be considered as third class brick. In crushing test, it crushing strength should be minimum of 10 N/mm² for first class brick, 7.5 N/mm²for second class bricks. In hardness test, we scratch the brick with nails. It should be scratch free. In soundness test we check the metallic sound by striking two bricks with each other.

Q21. What is void ratio?
Void ratio is the ratio of volume of voids to volume of solids.

Q22. What are the duties and responsibilities of civil site engineer in road and building construction?
While in duty of supervision of building, you should ensure that the concrete mixing is according to the grade specified. While supervision of road, you should ensure that the different layers of the road are laid in proper thickness.
Civil site engineer. Is responsible for execution of all construction activity allowed to him & he should take responsibility towards all scope of work under him. He should carryout work allowed to him.
There are two types of site civil engineer , first job is a supervisory one if he works with the consultant, in this case he needs to make sure that the document in hand is the correct designed.

Q23. What is responsibility of civil foreman ?
A Civil foremen duties/responsibilities is inspect on sides and management of each work on side and labor work, work quality also record of all work and each labor man & control work on time,on side accident, machines,material,tools. etc are full responsibility a side foremen.

Q24. What is shuttering? How it is done on site?
Shuttering is Temporary Structure. This Structure used for Placing of Permanent Structure according to Approved Drawing and Design. This structure generally Wooden or Steel.

Q25. How to differentiate the volumes of wet and dry sand / soil?
It should find out by Rapid moisture meter ,method moisture correction method.In Wet sand moisture become more and it dry moisture become less then wet.In sand moisture should be allowing only 12 %. 25% of Volume will be differ from the both.

Q26. Which is more efficient – rectangular beam or a circular beam? Give example?
According to material of beam if we use concrete then rectangular beam but on using steel beam tubular section are better than rectangular.

Q27. What is fineness of cement?
Fineness of cement is property of cement that indicate particle size of cement and specific surface area. and indirectly effect heat of hydration. if fineness is more then heat of hydration should be more.
To calculate fineness of cement sieving are done sieve number 9 and size of sieve 90 micron sieve

Q28. Describe briefly the various methods of concrete curing?
Curing is the process of maintaining the moisture and temperature conditions for freshly deployed concrete. This is done for small duration of time to allow the hardening of concrete. The methods that are involved in saving the shrinkage of the concrete includes:
(a) Spraying of water: on walls, and columns can be cured by sprinkling water.
(b) Wet covering of surface: can be cured by using the surface with wet gunny bags or straw
(c) Ponding: the horizontal surfaces including the slab and floors can be cured by stagnating the water.
(d) Steam curing: of pre-fabricated concrete units steam can be cured by passing it over the units that are under closed chambers. It allows faster curing process and results in faster recovery.
(e) Application of curing compounds: compounds having calcium chloride can be applied on curing surface. This keeps the surface wet for a very long time.

 Q29. Why are steel plates inserted inside bearings in elastomeric bearings?
In order to make a elastomeric bearing act/ function as a soft spring it should be made to allow it to bulge laterally and also the stiffness compression can be increased by simply increasing the limiting amount of the lateral bulging. In many cases in order to increase the compression stiffness of the bearing the usage of metal plates is made. Once steel plates are included in the bearings the freedom of the bulge is restricted dramatically, also the deflection of the bearing is reduced as compared to a bearing without the presence of steel plates. The tensile stresses of the bearings are induced into the steel plates. But the presence of the metal plates does not affect the shear stiffness of the bearings.

Q30. What reinforcements are used in the process of prestressing?
The major types of reinforcements used in prestressing are:
Spalling Reinforcement: The spalling stresses leads to stress behind the loaded area of the anchor blocks. This results in the breaking off of the surface concrete. The most likely causes of such types of stresses are Poisson`s effects strain interoperability or by the stress trajectory shapes.
Equilibrium reinforcements: This type of reinforcements are required where several anchorages exist where the prestressing loads are applied in a sequential manner.
Bursting Reinforcements: These kinds of stresses occur in cases where the stress trajectories are concave towards the line of action of load. In order to reduce such stresses reinforcements in the form of bursting is required.